The last project for my Advantage is a little induction work. I'm going to try adding a 2" carb spacer to the stock CJ manifold for now, but I'll be changing the intake in search of more r's. I have a Berk E with an A impeller, and my tach shows 4100 rpm. I have my doubts about that, but the pump is fresh. To the point..... for a jet, does a dual plane really make sense? I've heard 460s like to breath, and it would make sense to me that a single plane would help raise the powerband higher than a dual. Has anyone done a head-to-head (or even seat of the pants) comparison between the two?